Friday, 27 October 2017

About three weeks ago, I presented a recent drawing I did of Europe's megaherbivore fauna of the Holocene. I promised that I am going to present the aurochs of the drawing on a separate, refined version which is what I am going to do today. I do that because I think it is one of the most accurate aurochs artworks I did recently. It is not a reconstruction that is based on an actual skeleton, but it is based on such reconstructions. Actually, the basis for the drawing were the bull reconstructions that I did in June 2017. I did them by tracking out mounted skeletons (I corrected anatomical flaws in the mounts at first) to assure maximum precision:

For my recent life illustration, I used the Vig bull and Kopenhagen bull (c and d) as a model, and decided to do it in a running pose. Here is the result (I decided to watermark it as I repeatedly made the experience that my drawings have been used without permission and crediting, which is not pleasant):

While body shape and proportions are dictated by the skeletons and wild cattle anatomy, there are a few aspects that allow subjective decisions. For example, I could have given my aurochs larger horns. But as the horns of Holocene aurochs were smaller on average than those of Pleistocene ones (see here or here), I gave it medium-sized horns. The snout is slightly convex and the nose curves downwards a bit, which is a trait found in many Lidia bulls but also displayed by a skull of a British aurochs. Colouration also leaves room for speculation or subjective decisions (see here), such as the colour of the eel stripe, forelocks and extent of the lightly coloured muzzle. I gave my aurochs a yellowish eel stripe, as it is the most frequent colour in wildtype coloured bulls and written sources are not clear (they just speak of a "lightly coloured" stripe). The lightly coloured mouth is never mentioned in contemporaneous texts, and cave paintings show them only for cows. In wildtype coloured cattle, this trait is very prominent in almost all cows and also widespread in bulls, but aging bulls often have it reduced. In gaurs and bantengs, this trait does occur, but not in all individuals. So perhaps it was not that prominent in grown aurochs bulls as well. As for the colour of the forelocks, I decided to draw them black, as this is better supported by the evidence (see the post linked above). All in all, I am very happy with this aurochs drawing as it really shows a 100% of what I imagine a typical Holocene European aurochs bull to have looked like. Perhaps not surprising as it was me who did this drawing, but this is not always the case. The result also bears great similarity to many Lidia bulls (Spanish fighting bulls), but more on that on an upcoming post. My recent aurochs reconstructions and illustrations all have been rather bull-based, which is why cows are about to follow.

Wednesday, 25 October 2017

I have several posts in preparation at the moment, but for today, I have a short post. It is about a Heck bull I found recently on the web, and I think he is interesting for a number of reasons. It is or was (the article is from 2014, so I do not know if it is up to date) the breeding bull of a herd at Lembruch, Germany, owned by the breeder Martin Kockmeyer. At first I want to present some photos of the bull (photos owned by the Presse-Bild-Agentur Nokem Martin Kemper, I got them from this article):

First of all, the upper two photos show nicely how Heck cattle is a mosaic of its founding breeds: the body and skull shape of a Highland bull (not desirable from an "aurochs point of view"), the colour of a Werdenfelser or Corsican bull, the horns very reminiscent of Watussi. Secondly, the bull's name is "Arak", thus I suspect he might be from the Wörth lineage, which is/was remarkable for being the only closed breeding line within Heck cattle and having established large, thick, comparably well-curved horns. The bull also resembles those of the lineage, like "Albatross" or "Aretto" quite well. It is always good to see bulls from that lineage being breeding bulls on other herd, as it means that they are spreading the genetic make-up for good horns among the population. As it is apparent from the photos, the bull is seemingly not very large, which is unfortunately true of many un-crossed Heck bulls. On the VFA's sale site, there is currently a bull for sale from the same herd, named "Delika", born in 2014. The horns are of a very useful dimension and curvature, it might be a son of Arak:

Thursday, 19 October 2017

In my 2017
wild horse summary I had a look at what the evidence suggests regarding the
life appearance, extinction and population genetics of European wild horses. There
are some open questions, but also some things that we can say with certainty.
One of those things is that European wild horses are as extinct as the aurochs.
Nevertheless, there are three horse breeds that are often referred to either as
surviving wild horses or near-wild horses, having a special status among
European horses in being particularly close to the original wild form. Those
three breeds are the Polish Konik, the English Exmoor pony and the Portuguese Sorraia, and each one of those has its own proposed background story that is supposed
to link them closely to European wild horses. Those stories, however, are only purported
and believed by advocates of those breeds, people involved in various projects,
and are spread exclusively in non-scientific text books, public relations
articles, or on signs in zoos while nothing of them is replicated in scientific
literature, and none of those breeds are considered zoologically special among
domestic horses. Advocates of the breeds blame a “conservative scientific
mainstream” that is biased against the idea that the European wild horse might
still be extant in some form, while the truth is that the background stories
for the purported special status of the Konik, Exmoor or Sorraia are largely
based on wishful interpretations, Chinese whispers and fabrications, actually
making those stories myths that do not withstand objective examination.

Here I want
to present and subsequently dismantle those myths. When not relying exclusively
on sources that repeat the same stories over and over, but actually provide a
deeper background knowledge, backed up by more evidence than usually delivered,
it becomes rather obvious that the usually purported background stories for
those breeds are not tenable. Yet those stories are pretty persistent and widespread, and I hope this post might become a little contribution to clear things up.

The Konik myth:The
Polish game park at Zamosc was the place were Europe’s wild horses survived
longest. In the year 1806, these wild horses were donated to local farmers of
the Bilgoraj region and incorporated to their farm horse stock. In the 1920s,
the Polish agriculturist Tadeusz Vetulani started a breeding-back project using
wild horse-like individuals from the Bilgoraj region and bred them selectively
for a wild horse-like nature, eliminating the domestic influence their genome
experienced in the hundred years before. He called the result “Konik”.

The truth behind it: Whether or not the supposed wild
horses at Zamosc were truly wild and not feral, it is unlikely that they left a
noticeable trace in the local farm horses. This claim is based on a notion by
Julius Brincken in a book from 1826, but this book is full of errors, misinterpretations
and fabrications, so it is not a reliable source. Furthermore, the Zamoski
family was at war with the local farmers due to social unrests in the 1780s and
1790s, so it is unlikely that they would have provided them with generous gifts
in the form of livestock. And even if they did, it is unlikely that the farmers
tolerated a strong wild influence in their horses as it would have been a
throwback in their productivity and suitableness for agricultural work, as wild
horse hybrids used to show intractable behaviour [2]. And even if they
incorporated wild horses, and perhaps only mares, into their stock, not much
would have been left after 100 years. So it is very unlikely that the horses of
those particular rural regions of Poland had a notable wild horse influence in
the 20th century [1,2].

In Poland,
there was/is a landrace called Panje horses. Those horses were very robust, of
a small and stocky body and varying in colour between black dun, black, sorrel
and bay. In an 1921 article, Panje horses were considered as possible wild
horse descendants (which is to be refuted for the reasons stated above) by the
researchers Gabrowski and Schuch. This drew the attention of Polish
agriculuturist Tadeusz Vetulani to the Panje horse as “wild horse relict”, he
tried to back up this suspicion with cranial measurements (that have been
questioned [1]), and coined the name “Konik”, which successively replaced the
name Panje horse. Private and public studs were created in order to preserve
and spread the landrace. In 1927, Vetulani started an experiment that is often
considered a “breeding-back” experiment, but was actually more of a
dedomestication attempt, using Konik/Panje horses that he considered wild
horse-like. But Vetulani’s herd was only one of many Konik lineages back then,
and the Second World War created a lot of confusion, as many Koniks were moved
all over Poland and Germany during and after the war. After the war, the stud
at Popielno was the most important Konik breeding site. They performed two
separate ways of breeding: one to continue Vetulani’s way of few human
interference, and one of traditional indoor breeding and commercial sales. Popielno
was one of many breeding sites, and when other countries started to become
interested in this breed, they purchased from any stud available [2].

Thus,
neither was Vetulani’s experiement an experiment of selective breeding, nor was
it the ancestral stock of the modern Konik population but merely one of many
lineages [2]. He did not create the breed, but merely coined the modern name of
the breed. The fact that 10-5% of the modern Konik still show a black or sorrel
colour or white streaks on the forehead (respectively) reveal the mixed origin
of this landrace [2], and there is no compelling, not even plausible, evidence
that their ancestral stock was strongly influenced by wild horses [1,2].

The Heck
horse, which is often presented as a “recreated Tarpan” in Germany and also
other countries, is in a sense a washy Konik – it was created by the Heck
brothers in the 1930s and 1940s by crossing Icelandic horses, Gotland ponies
and Dülmen ponies with a Przewalski stallion. Later on, Koniks were used
massively as breeding stallions on Heck horses, so that they are heavily influenced
by that breed, hence the large optic resemblance [8]. The same was the case in
the Dülmen pony, which is why the three breeds sometimes are regarded as the
Konik group [8]. The Liebenthaler horse can also be regarded as a member of
this group.

The Exmoor Pony myth:The
Exmoor Pony is a remnant population of a wild horse type or at least a feral
type of very original western European horses that once ranged on the entire
British island. Several other populations of this primitive British horse type
have been intermixed with derived horse breeds, creating the modern British
pony breeds such as the Welsh Pony, New Forest Pony, Dartmoor Pony and others. The
Exmoor Pony however is the only population that retains a stable, wild
horse-like appearance with a brown colour, countershading + white muzzle and a
sturdy body. The similarity to other northern ponies such as the Gotland or
Faroe Pony, and especially some primitive Iberian breeds such as the Garrano
and Pottoka, endorse the hypothesis of a north-western European wild
horse/primitive horse type that once was found in this region and is most
authentically represented in the form of the Exmoor pony.

The truth behind it: At first, this scenario sounded
convincing to me. But what is most important to note first is that equines
disappeared from the archaezoological record of the British isle at the end of
the Mesolithic until domestic horses were introduced by the Celts [3,4,5].
Therefore, the Exmoor pony cannot be a remnant wild horse population or wild
horses with domestic introgression, they have to be of domestic origin. But
this alone does not rule out that they are the last representative of a
homogeneous, feral and primitive horse population that once ranged across the
entire British isle. One argument is their homogeneously small body, comparably
short mane, the brown colour with countershading plus white muzzle. However,
careful examination suggests that the population at the Exmoor never was
homogeneous after all[4]. There are no helpful references prior to the 18th
century on the colour variants found in the Exmoor population. Between 1805 and
1809, 81 Exmoor ponies were sold from the moor. Their colour was documented and
included black, grey, bay, dun, chestnut and one piebald individual. There is
no evidence that purposefully “non-pure” Exmoor ponies were caught in this case.
Two illustrations in the Illustrated London News from 1835 clearly show horses
with a long mane, their colours are probably implemented to be brown with a
white blaze and sock, grey and a black one [4]. A notion by Worthley Axe in the
year 1906 is even more revealing: “… the majority of the so-called Exmoors are
simply mongrels” [4]. The Acland herd, which made a considerable contribution
to the modern Exmoor population, also included a number of greys and blacks in
1900. There is a record that suggests that black Exmoor ponies were selected
out because they lacked the expression of the white muzzle, indicating that
artificial selection started back then. Furthermore, the Exmoor pony population
went through several bottlenecks, the most severe in course of the Second World
War. A stud book for the breed was set up in 1921, at first black and grey
individuals were tolerated but selected out later. It is thus far more in line
with the evidence that artificial selection and genetic bottlenecks created the
homogeneous external appearance we see in the modern Exmoor pony, and there is
no evidence that it was homogeneous prior to 1906. Most likely the Exmoor pony
that is always brown in colour with countershading, a white muzzle and no white
markings is an invention of the 20th century [2]. It would therefore
also be more parsimonious to assume that other British pony landraces like the
Welsh pony, Dartmoor pony or New Forest pony never were homogeneous either. Furthermore,
the use of British ponies including the Exmoor pony on Iberian breeds like the
Pottoka in the 20th century is well-documented[2], which is at least
partially responsible for the optical resemblance. Thus there is no empiric
basis for a once feral, primitive free-ranging horse type that looked like the
Exmoor and ranged across Great Britain or even whole western Europe.

Also, which
is important to note, Exmoor ponies most often display a colour variant that is
called seal brown, At. This
is an allele that has not been identified in wild horses yet, in contrast to
the two wildtype alleles bay A+ and
black a [6,7], and therefore most
likely is a domestic colour. The black individuals, which have been actively
purged from the population, however, would have displayed a wildtype colour
variant [6,7].

The Sorraia myth:The Portuguese
agriculturist Ruy d’Andrade spotted a herd of strongly striped, free-ranging
horses in a remote region in Portugal. He considered them to be a remnant
population of the zebro, a strongly striped Iberian wild horse type. He was
unable to find them again, but collected a number of farm horses from that
region that he considered to be closest to those horses, and started to breed
them. This is the modern Sorraia horse, by some even communicated to be
identical to the zebro and thus a wild horse.

The truth behind it: The claim that the Sorraia is a
surviving Iberian wild horse is flawed by the story itself – d’Andrade did not
catch any wild horses and started breeding them, but merely collected farm
horses he considered to be reminiscent of the horses he spotted. He collected
four local stallions and seven mares, and a Criollo stallion was added later
on. Therefore, the Sorraia is a descendant of domestic farm horses. But is it
possible that is particularly strongly influenced by an optically identical
Iberian type of strongly striped wild horses, the zebro? First of all, there
are not any references suggesting a survival of wild horses on Iberia into the
beginning of the 20th century. C.H. Smith reports free-ranging
horses of black dun and bay dun colour with wild markings that ranged from the
Camargue, parts of Spain to the Ardennes, Great Britain and Scandinavia (see
here), but also describes them as “sturdy mountain-forest ponies”, and it is
not clear if those are wild or feral horses anyway. Regarding the actual zebro,
it seems that this population of equines vanished in the 16th
century [8] and many authors tend to consider them feral donkeys instead of
horses. Indeed a genetic test of the skeleton of the supposedly last zebro
turned out to be a donkey [9]. The strongly striped ashy grey colour of
wildtype coloured donkeys is very reminiscent of the black dun colour scheme in
horses.

The
allegedly strong stripe pattern of the Sorraia is often purported as its
trademark and an indicator of particular primitiveness that links it to the
zebro. However, stripes are part of the bay dun and black dun colour scheme and
found in many horse breeds. Therefore, it does not give the Sorraia any special
status (see a very strongly striped Hucule here, for example).

Ferus-type wild horses are usually assumed to have
been comparably small and sturdy in build. The Sorraia, however, is comparably
large (140-150cm at the withers) and lanky. As there is no comprehensive
archaezoological record of predomestic wild horse skeletons that has been
osteometrically examined (only some single fragmentary specimen) it can neither
be proven nor ruled out that Iberian wild horses were larger and more gracile
in build than other Eurasian wild horse types, but it would be necessary to
have evidence at hand for making such a claim.

More
importantly, genetic information has revealed the Sorraia as a domestic horse
[10].

I am going
to come back to genetic studies more extensively in the next part of the wild
horse series 2017. A closer look at the respective history of those three
breeds that are often supposed to be wild horse relicts, near-wild horses or
recreated wild horses alone is sufficient to show that there is actually
nothing of substance that suggests that these three breeds deserve a special
status among robust landraces of European domestic horses. But this of course
provokes the question which horse breeds are best suited to be used as a
substitute for the European wild horse in ecologic restoration. Thus, the
upcoming post is on this question as much as on the domestication of the horse
in general.

I think that Apollo might approach the age of reaching its final colour, but it is obvious that he is darker in colour than its halfblood sister. This is likely mostly due to its Maremmana ancestry, but sometimes also Watussi cattle show a tendency of sexual dichromatism. The zebuine hump seems to be either lacking or very weakly developed yet, but this is irrelevant as those individuals are F1. Surely the hump might or might not reappear in future cross individuals, depending on coincidence. One always has to pick the right individuals once the genes become split up and distributed among the offspring. Regarding the colour, I think this combination bears the potential for very dark or even black bulls (probably with a colour saddle) in F2 and subsequent combinations. Watussi might pass on alleles for very dark bulls, but is unable to express it since their coat colour seems to lack the black pigment eumelanin. Maremmana enables that, but carries dilution alleles that remove red pigment, pheomelanin. Watussi, however, contributes the wildtype alleles that enable the expression of pheomelanin. Thanks to the 2. Mendelian rule, it is possible that true F2 individuals might end up showing the right wildtype aurochs colour setting. I am confident that it is possible to boost the horn size of the Auerrind crossbreeds using Watussi without adopting the negative traits of the breed using careful selection and also a bit of luck. It worked successful with Heck cattle of Neandertal descent, and in Hortobagy there are a couple of qualitatively aurochs-like Taurus cattle with Watussi influence. Thus, I am looking forward to watching those individuals grow up and to see their respective offspring with great interest.

I know of
course that wild boar are actually omnivores. One might ask why I included fallow
deer, as it was introduced in historical times just like the mufflon. In
contrast to the mufflon it has a Pleistocene interglacial record in Central
Europe, which is why I included it here. The question is whether Dama dama would have recolonized Europe without
human influence. In order to answer the inevitable question “but where are
elephants and rhinoceroses?”, my drawing intends to illustrate only those
herbivores which had a solid presence in Holocene Europe. It is not known for
certain that the European continental elephant species Palaeoloxodonantiquus as
much as the two rhino species of the genus Stephanorhinus
have been driven to extinction by men and would still be extant without
anthropogenic influence today. It is plausible, I even consider it likely, but
not proven. One might also ask where water buffalo and Equushydruntinus, the
European wild ass, are. There is only one Holocene remain for the genus Bubalus in Europe (Austria, to be
precise) which has been tentatively assigned to this genus by Erich Pucher in
1993, nowadays he would reclassify it as Bos
(personal communication). Bubalusmurrensis might have been hunted to
extinction (although its record is really rare and I do not know of literature
mentioning its association with kill sites), but here goes the same as for
elephants and rhinos. Europe being recolonized by extant members of Bubalus without anthropogenic influence
is speculation. Equushydruntinus has a solid Holocene
evidence in Neusiedl, Austria (Pucher, pers. com.), but as part of a different
biome – the Puszta steppe.

When I
refer to a mixed-forest zonobiome I do not intend to imply it was naturally all
forested. I consider the classical hypothesis of this biome being one closed
canopy forest falsified by a number of facts. However, I also consider it an
exaggeration to speak of a European savannah, as there is also evidence
pointing against such a hypothesis. To me it is most likely that this biome was
a mosaic of open, semi-open and closed landscape, depending on a variety of
factors also including such as latitude, precipitation, flooding and humidity,
natural disasters and so on. This a complex, big and (needlessly) heated debate
that is way to extensive for this post and my drawing. I could have drawn my
megaherbivores on a grassy background, which would be only one of several
habitats we might have encountered those animals, but sporadic oak trees and
hazel bushes are certainly a realistic background as well considering they have
been pushed in those habitats as civilization progressed and the space for wild
herbivores became increasingly limited.

I decided to
give my wild horse a bay dun colouration, as bay dun is suggested to have been
most frequent in Holocene wild horses by genetic evidence. Historic evidence,
which is dubious, would have favoured black dun, but both colour variants plus
the non-dun variants are proven for ferus-type
wild horses. For details, see my wild horse summary 2017.

And here a
close-up view of the aurochs:

I am very
happy with this one, I managed to get it exactly the way I imagine Holocene
European aurochs bulls to have looked like. It is based on my reconstructions
of several skeletons that I published in July 2017 and I think it bears a striking
similarity to many Lidia bulls. I am going to post a refined version of that
close-up drawing soon.

Friday, 6 October 2017

It has been
long ago that I posted something extensive on wild horses here on my blog,
which is why I decided to do a summary of all my past posts on the biology of western
Eurasian wild horses. I have been digging through a lot of literature since
2013 and am also going to add some new information. I hope you find useful.

Definition & population genetics

At first I
want to define what kind of wild horses I have been focusing on. As long as we
regard Przewalski’s horses as members of the same species as domestic horses, Equus ferus, which is what I do, this
species is composed of two major clades: one leading to the Przewalski’s horse,
Equus ferus przewalskii, and one
leading to domestic horses including their wild progenitors, Equus ferus ferus (=Equus ferus caballus). Genetics suggest a separation of both
lineages between 160.000 [1] and 38-72.000 years [2]. On my blog, I have been
focusing on these extinct wild horses that spread from Iberia to the Eurasian
steppe and were domesticated about 6000 years ago.

This is
where it gets complicated now, as there are several more or less open
questions: How long did true predomestic ferus-type
wild horses survive in Europe? Are the historic accounts referring to true
predomestic wild horses, hybrids with feral horses or feral populations and
wild horses were already extinct by that time after all? Where was the line
between the geographical range of the ferus-subspecies
and przewalskii-subspecies? (the
later question is hardly addressed in the literature).

Not only
are these questions hard to answer, there are also some uncertainties on how to
refer to these populations. A very popular term is “Tarpan” (in the
German-speaking non-scientific literature, it is also very common to
distinguish between a “forest tarpan” and a “steppe tarpan” – a distinction
that mostly came about by “copy+paste” and is baseless [3]). This term is
problematic, as there is no certainty on what kind of animals it originally
described. It has become a trend to either condemn the term, or to strictly
define it as the term for predomestic, ferus-type
wild horses, no matter what it originally described. You have to choose it based
on your taste. But if you choose for the latter option, you have to be aware of
the fact that “tarpan” has no tradition of being colloquially used for the
native European wild horses. It never was a colloquial term outside of the
steppes in the way “deer”, “wolf” or “aurochs” was. It has been introduced in
scientific literature in 1763 [3], so it is just convention-based. In my 2013
post What do we mean by “Tarpan”? I chose this option and continued to used
this term for another few blogposts. However, nowadays I avoid using the word
“tarpan” because of all the confusions and also the connection to baseless
concepts like “forest vs steppe tarpan” or the Konik-story and others (more on that in an upcoming post). Then I
increasingly referred to the ferus-type
wild horses as the European wild horse(s), or the Western wild horse(s) (in
contrast to the Eastern wild horse, the Przewalski’s horse).

Today I
still like to use the latter two terms, usually in plural, as we do not know
how many local types there were. Ancient DNA samples indicate two separated
predomestic populations on western Eurasia for the Holocene, one on the Iberian
peninsular and one extending to the Eurasian steppe [4]. That does not mean
that the Pyrenees were the mark were we can find phenotypic differences between
the horse populations. It means that at least for some time it was a reproductive
barrier. It is possible that there were indeed phenotypic differences between
the wild horses dwelling the European mixed forest regions and those in the
steppes, as both are two very different biomes. For that, we have to look at
the evidence. Furthermore, any differences between wild horses of the European
mixed forest biome* and the western steppe biome must have been more or less
continuous, because so were the populations.

*I do not
claim this biome was densely forested all over. This is not likely by current
evidence, but neither is a “European savannah”. Rather, I assume a mosaic of
open, semi-open and closed habitat for this biome.

Coat colour genetics

Historic
references are a problematic source as it is not clear what kind of free-roaming
horses they actually referred to. Ancient DNA, however, can at least provide a
clue on the colour phenotypes present in predomestic European horse
populations. A number of studies have been conducted in the past, identifying
colour alleles in prehistoric European wild horses.

We mainly
have to deal with four colour phenotypes that have been proven for predomestic
horses, that I briefly introduce now:

Bay: This phenotype is caused by the expression of
the dominant allele A and recessive non-dun1. Wild markings like the dorsal
stripe are still visible (non-dun2, however, is a domestic mutation that does
not show the wildtype markings).

Bay dun: This colour is produced by the bay base colour
plus the dominant Dun allele. Wildtype
markings are more or less clearly visible (dorsal stripe, shoulder stripes, leg
stripes)

Black: Black is recessive under bay and caused by the
a allele.

Black dun: Black dun is caused by a black base colour
plus the dun allele. It is also referred to as “grullo”, “blue dun”, “mouse
dun” and other terms and present in various shades. Wild markings are more or
less clearly visible.

(There is
also evidence for the so-called “leopard spotted” wild horses [5], but I leave
this colour variant aside for now)

Bay dun is
also found in other wild equines such as the onager, kiang and Przewalski’s
horse, and therefore was ancestral for the ferus-lineage.
It is also dominant over all the other colour phenotypes. Bay was the only Agouti allele in the Pleistocene, as the
black variant is a mutation that occurred on the Iberian peninsular during the
Holocene, where it started to outnumber bay and spread eastwards [6],
indicating some selective advantage. What is interesting is that the non-dun1
mutation existed 42.700 years ago at least, and side by side with Dun[7]. Therefore in the Pleistocene,
wild horses of the same population either showed a bay dun or bay phenotype
(the former might have been more common as it is dominant), while for the
Holocene of Europe we have four possible phenotypes – bay dun, bay, black dun
and black – as there was no regional or chronological gradient for the dun
factor found. In sample of Pruvost et al. for Holocene wild horses of Europe
and the steppe, the bay allele was found more often, while in Ludwig et al.,
the black allele was found to be prevalent on the Iberian peninsular (75%).

This of
course provokes two very interesting questions: what was the selective
advantage of the black allele (Ludwig et al. speculate that this colour variant
was of advantage in an increasingly forested habitat in the Holocene, I
consider that plausible), and why where ferus-type
wild horses one of the very few large vertebrate species that apparently was
heterogeneous in colour? One explanation for the latter question is that maybe
we are looking at a mutation-and-selection process that was under its way there
and perhaps, if the populations had not been driven to extinction by man, would
have become homogeneous in colour after a couple of further millennia of
evolution.

Back in
2013, I illustrated the four respectively five colour phenotypes that occurred
in the wild ferus subspecies of the Holocene:

The drawing
also shows countershading in combination with the white muzzle (“mealy mouth”).
It is, based on parsimony, ancestral for the ferus-lineage as well, but as far as I know the genetic background
for it has not been resolved yet and also not been tested in aDNA samples,
which is why its presence on my scheme is speculative. Countershading can be
visible on a black dun phenotype, but never is the white muzzle. This drawing
that I recently did shows a bay dun wild horse without countershading and white
muzzle (it is actually part of a larger drawing that I am going to present in
the next few days):

As an
interesting side fact, the sorrel mutation of domestic horses apparently found
its way into wild horse populations via introgression (Pruvost et al.).

Coat colour
is of course only one aspect of the animals’ life appearance. For the
morphology of ferus-type wild horses,
we have to look at other sources. If you wonder why I illustrated my wild horses
with a falling mane, I am going to come back to that later on.

Osteologic material

Due to the large
osteological similarity between wild and domestic horses, it is very difficult
to distinguish between both types in the subfossil record. Usually, when the
bones are associated with human material, they get assigned to the domestic
type unless they show signs of hunting, but the only way to distinguish them
safely is on genetic level (I do not know how the studies for wild horse coat
colour genes detected wild horse material, but I hope it was one genetic
level). In the literature you barely find any remarks on the morphology of
Holocene ferus-type wild horses based
on osteologic material, and you also never see mounted skeletons of such horses
in museums. While it is probably true that the mixed-forest biome is not the
primary habitat of horses (I am not claiming that this biome naturally
consisted only of closed forests, not at all), Holocene European wild horses
could not have been that dramatically rare that one does not even have enough
material for a couple of mounted skeletons. I suspect the true reason is that
most Holocene subfossil equine material not directly associated with humans
have been assigned “Equus sp.” and
have been getting dusty in collections since then. I suggest testing some of
this material and collect a number of genuine subfossil wild horse specimen,
and I am confident that there is enough material for at least a couple of
mounted specimen that could give us a clue on the actual morphology of Holocene
European wild horses.

The only
remarks describing the morphology of alleged European wild horse material were
referring to comparisons with Exmoor and Konik bones – not surprisingly, the
authors reported large similarity [8,9]. I say “not surprisingly” because the
morphology of Holocene ferus-type
wild horses was probably comparable to a robust pony type as this body type is
also typical of Pleistocene remains and the Przewalski’s horse. However, one
has to be careful of self-fulfilling prophecies – that is, if there were indeed
ferus-type wild horse remains with a
warmblood-like morphology, they might automatically become assigned to
warmblood-type domestic horses because our conception of wild horses expects us
only to find pony-like remains. What I am saying is that it cannot be bad to
strengthen this conception on empirical grounds by examining the subfossil
horse record more thoroughly, also to get an idea of regional variation (f.e. it
could be possible that wild horses got larger and more long-legged towards the
Eurasian steppe as the habitat becomes more open).

Historic accounts of free-roaming horses in
Europe and the steppes

As genetic
information so far only told us about the coat colour of ferus-type wild horses in Europe, and osteologic material has not
been examined thoroughly enough yet to draw solid conclusions on morphology,
size and regional variation, we also have to rely on human sources of information:
that is, contemporaneous art and written sources. I know of no historic
artworks showing supposed European wild horses (except for a “Tarpan” by C. H.
Smith from the 19th century, that is way too generic). I do not use
Pleistocene cave paintings as source material as the climate and therefore the
biome and consequently the wild horse type of the Pleistocene in Europe were
not comparable to those of the Holocene.

Written
historic sources are problematic for the reasons I outlined above in the beginning
of the post. It is not known when original, un-hybridized ferus-type wild horses died out. It could be that they died out in
prehistoric times already, and that all historic accounts refer to feral
domestic horses that exhibited more or less primitive traits. It is also
possible that these populations were hybrids of wild and abandoned/escaped
domestic horses. For the texts referring to free-roaming horses of the Russian
steppe it becomes increasingly complicated because it is not known how far
westwards the original range of the Przewalski’s horse extended, and if those
wild horses described in the texts were actually either Przewalski’s horses or
hybrids between those and feral horses, and not ferus-type wild horses.

One aspect
why some authors discard all historic accounts of free-roaming horses a priori
is that they seem to mention falling manes. A falling mane has long been viewed
as a domestic trait, as all extant wild equines have a short erect mane. However,
this conception is out-dated. Frozen Pleistocene mummies assigned to Equus lambei, a taxon suggested to be
conspecific with Equus ferus [10],
have a falling mane, showing that this trait arose well before domestication.
It has been suggested that a falling mane and a bushy tail evolved as a
protection from precipitation [9], and indeed all extant equines with an erect
mane live in arid environments with low precipitation. So it is not unlikely
that the Holocene wild horses of Europe had a falling mane. It is also most
likely that the ancestral population of the domestic horse and the last common
ancestor with E. lambei had a falling
mane, otherwise this trait evolved twice.

Therefore,
a reported falling mane is not an indication of feral horses. There are also
authors that read “short mane” (a term used in some of these accounts) as an
evidence for erect manes in Holocene wild horses of Europe, but “short” does
not automatically mean “erect”, it can also describe a short but falling mane.
And most commonly, the sources write of “short and frizzy” manes, indicating
the manes were actually falling or at best semi-erect (what also occurs in some
domestic horses).

It is not
impossible that genuine, un-hybridized wild horses survived in Europe and the
steppes until the 19th century. As the subfossil record of
predomestic equines is understudied, there is no hint that these populations
disappeared before historic times. It is possible, but the contrary is just as
likely. However, it is questionable how pure these populations were. Wild
horses were reported to steal domestic mares from farms, which is one of the
reasons why they were persecuted by man, and must have led to occasional
domestic introgression into wild populations. But the influence of escaped or
abandoned cavalry horses that ran wild must have been more dramatic, something
that happened for centuries. Wild and domestic forms usually tend to hybridize
wherever they share the habitat, which is also apparent in canines and pigs. Furthermore,
the notion by Pruvost et al. that the sorrel mutation found its way into
predomestic populations shows that hybridization did took place.

I believe
the truth is that we cannot know what the true identity of the historic
free-roaming horse populations of Europe and the western Eurasian steppe was. A
number of the historic accounts describe horses with morphological and
behavioural traits expected or suspected for wild horses: a small, sturdy body,
short mane, large head, wildtype colour (as explained above, there are four to
five wildtype colour variants for ferus-type
wild horses), shy behaviour that is either untameable or tameable to a certain
degree after some time (other wild equines also can be tamed more or less). Due
to the morphology and behaviour that is described, I think it is quite
plausible that at least some of these populations represented actual wild
horses, with a varying degree of influence from domestic horses. Nevertheless, suspected
wildtype traits described in those populations would also be found if they
descend from rather primitive landraces. And once again, we have to beware of
the danger of self-fulfilling prophecies or circular reasoning.

In my 2014
post Western wild horses: What does the evidence actually say? I presented all
sources of written accounts on putative ferus-type
wild horses that I was able to find. I noted whether I got it from a primary
source (therefore the actual text itself), a secondary source (a text that
describes what is written in the actual source) or a tertiary source, in order
to prevent the danger of Chinese whispers. Another inevitable problem is the
language issue, especially with sources from the antiquity. Furthermore, there
can be confusion over equine colour terminology because the terms changed over
time. For example, “dun” used to refer to bay dun exclusively, and it is still
used this way in the UK today, while in the strict modern terminology backed up
by a genetic basis “dun” refers to a modification of pigmentation that can act
upon variable base colours. Thus notions of an “Isabella” or “tan” colour from
the 18th century must not be the same genetic colour variant as in
modern terminology. The interpretation of “mouse-colour”, which is mentioned
rather commonly in those historic texts, is subjective as well. It is usually
interpreted as referring to black dun horses, which is plausible, but it is
also possible that individual authors had other colours in mind.

I copy the
summary of historical sources from 2014 into this post, also giving a personal
interpretation. A P indicates a primary source, a S a secondary source, and a T
a tertiary source.

Herodot, 5th century before Christ: lightly
coloured (leukos) wild horses in the Ukraine. (S) [8] I am not a
classical philologist, but I read that “leukos” can either be translated with
“white” or “light-coloured”. A white colour would indicate a domestic origin of
the horses described, light-coloured can indicate dun (and therefore wildtype
colour) among other colours.

St. Isidore, 600: Iberian wild horses: colour like a donkey,
ash-coloured. (P) [11] He is probably referring to black dun horses, as this
colour scheme is rather similar to that of a donkey.

F. Chr. Dahlmann, 1840: Large numbers of wild horses that were
hunted lived in Denmark of the 12th century (T). [8] No
information on the looks of the horses is given.

H. Röslin, 1593: Wild horses were still living at Vogesen,
Elsass-Lothringen. They were faster and wilder than deer and difficult to
catch. Once caught, they got tame after some time (S). [8] No information on
the looks are given, could be either feral or wild horses.

Balthasar Haquet, 18th century: Wild
horses at Zamosc: small, blackish brown, large and thick heads. Mane and tail
comparably short, stallions had a beard. Were used in fight shows with
predators and showed great bravery (S). [8] The described morphology suits the
prevalent conception of wild horses, and “blackish brown” colour could either
refer to black dun or other (in this case domestic) colour variants.

Eugeniusz Rozdzynski, 1721: Wild horses at Zamosc: tan and isabelline
in colour (T). [8] “Tan” can indicate a lot of colour variants (bay, seal
brown, dark expressions of black dun, chestnut), and isabelline could either
indicate isabelline in the modern sense or any light colour, in which case dun
variants would be among them. Thus, the description could refer to the wildtype
colour variants, but also others.

Rytchkof, 1762: colour dun or bluish, other shades
exceptional (S). [11] “Dun or bluish” most likely refers to both bay dun or
black dun, or various expressions of black dun.

Samuel Gottlieb Gmelin, 1768: Wild horses at Woronesh, Russia. The
largest of those wild horses barely reached the size of the smallest Russian
domestic horses. The ears were very pinned and the size of domestic horses or
sometimes longer and hanging down. The eyes were fierily. The mane was short
and frizzy, the tail shorter than in domestic horses. The were typically
mouse-coloured, but white or grey horses were also reported. The belly was ashy
at the base, the legs were black from the knees downwards. The hair was long
and dense during the winter and felt more like fur than horse hair. (P, S). [8]
It seems plausible that the author was indeed referring to black dun, white and
grey. The morphology fits what is expected for wild horses.

Peter Pallas, 1771: Free-roaming horses at eastern Prussia and
western Siberia. Considered them feral domestic horses. Resembled Russian farm
horses, but they had thicker heads, pinned ears, short and frizzy manes and
shorter tails. They were of a greyish brown colour and had lighter coloured
legs, brown and greys would appear. The colour of the head was white/light on
the snout and black towards mouth. Black horses were rare, and there were no
piebald ones. They lived in herds of 20 individuals. (S) [8,11] “Greyish brown
colour” probably indicates black dun, but “lighter coloured legs” would not fit
this colour variant, as it includes dark coloured legs. However, as he also
mentions other colour variants, it is not clear which of those had lightly
coloured legs. Both “brown” (might refer to bay) and black colours are possible
for ferus-type wild horses.

Kajetan Kozmian, 1783: Wild horses at Zamosc: small, strong
limbs, enormous strength and uniform dark mouse colour (S). [8] The described
morphology is plausible for wild horses, dark mouse colour probably refers to
black dun and the notion that the colour was uniform might indicate that the
herds he saw were not admixed.

C. H. Smith, 1841: (Probable) Wild horses in the Russian
steppe: “coupled with different proportions and position of the ears,
an arched or plane forhead, a straight or curved nose, a difference of colour
in the eyes, of the skin, of the hoofs, the constancy of their liveries, of
their marks, in a streak along the back and bars on the limbs, of dappled
croups and shoulders, or of dark uniform colours, dense or thin manes and
tails, although traits now mixed,” […] “All seem to refer to a
sturdy form of mountain-forest ponies, still found in the province of Cordova,
in the Pyrenees, the Vogesian range, the Camargue, the Ardennes, Great Britain,
and in the Scandinavian highlands: all remarkable for an intelligent but
malicious character, broad forheads, strong lower jaws, heavy manes, great
forelocks, long bushy tails, robust bodies, and strong limbs; with a livery in
general pale dun, yellowish brown and a streak along the spine and cross bars
on the limbs, or the limbs entirely black, as well as all the long hair and
mostly having a tendency to ashy and gray, often dappled on the quarter and
shoulders”. […]“These horses are evidently again referred to by
Andr. Schneebergius, who states, that “there were wild horses in the preserves
of the prince of Prussia, resembling the domestic, but mouse-coloured, with a
dark streak on the spine, and the mane and tail dark;” […] “Real
Tarpans are not larger than ordinary mules, their colour variably tan, Isabella
or mouse, being all shades of the same livery, and only varying in depth by the
growth or decrease of a whitish surcoat, longer than the hair, increasing from
midsummer and shedding in May: during the cold season it is long, heavy, and
soft, lying so close as to feel like a bear’s fur, and then is entirely
grizzled; in a summer much falls away, leaving only a certain quantity on the
back and loins: the head is small, the forehead greatly arched, the ears far
back, either long or short, the eyes small and malignant, the chin and muzzle
beset with bristles, the neck rather thin, crested with a thick rugged mane,
which, like the tail, is black, also the pasterns, which are long: the hoofs
are narrow, high and rather pointed; the tail, descending only to the hocks, is
furnished with coarse and rather curly or wavy hairs close up to the crupper;
the croup as high as the withers: the voice of the Tarpan is loud, and shriller
than that of a domestic horse; and their action, standing, and general
appearance, resembles somewhat that of vicious mules.” (P) [12] For
Smith’s full text, go here.

C. R. Darwin, 1868: “It seems that not very long ago a wild
breed of dun coloured horses with a spinal stripe was preserved in the royal
parks in Prussia. I hear from Hungary that the inhabitants of that country look
at the duns with a spinal stripe as the original stock, and so it is in Norway”.
(P) [11] He is probably referring to the population at Zamosc.

Heptner, 1989: Last living Tarpan (Dubrowka Tarpan), died
1918. It was 140-145 cm tall, had a large head, small ears, short neck,
mouse-coloured coat, broad dorsal stripe, faint shoulder stripes, black mane,
tail and lower legs, semi-erect mane, broad and arched front head and a
straight head profile. (S) [13]

I have not commented
the remarks of Smith and Heptner yet because I treat the problematic of the steppe
horses as a separate issue. At first, I want to come back to the horses of
Europe western to the steppes. The colour that is mentioned most frequently is
probably black dun. While in genetic samples bay was the prevalent base colour,
there was a tendency of the black allele becoming increasingly common, as
mentioned above. If this trend continued to historical times, the black allele
might have outnumbered the bay allele. So the prevalence of black dun horses in
written accounts is plausible for wild horses. For Iberia, St. Isodore
mentioned probably black dun horses exclusively (“donkey coloured”), while
Smith describes a southwestern European horse type that might have displayed
both bay dun and black dun (“pale dun and yellowish brown” vs. “ashy to grey”).
Therefore, the described coat colours often match with what is expected from
genetic information. But it cannot be denied that many of the sources also
mention colour variants not proven for wild horses, i.e. most likely domestic
colours, such as white/grey and perhaps the notion of “isabelline” and “tan”
horses (however, both words can also indicate bay and dun horses, which would
be wildtype colour variants). It is of course possible that all those free-roaming
horse populations were feral, primitive rural horse type and hence the wild
horse-like behavioural and optical traits. But it is, in my opinion, just as
likely that they do represent wild horse populations that mixed with abandoned/escaped
domestic horses to a varying extent. It is a tricky situation: it would be as
if it was not known when genuine aurochs eventually disappeared, but there
would be historic accounts of very aurochs-like bovines ranging freely, looking
a lot like aurochs but some individuals having diverging colour or horn
variants. True aurochs, feral primitive cattle, or hybrids?

Only a
genetic test of a representative sample of individuals from those populations could
provide clarity.

For the western
steppes, it becomes even more complicated, as it is not clear how far westwards
the Przewalski’s horse originally ranged. Artworks from the 4th and
5th century before Christ resemble Przewalski’s horses in having an
erect mane and a short-haired tail base [14], which makes it likely to me that
this subspecies extended at least until the south-western edge of the steppes. The
records of putative wild horses from the western steppes could easily also
refer to Przewalski’s horses or hybrids of Przewalski’s horses with feral
horses. Especially the notion of the “Tarpan” resembling “vicious mules” is
reminiscent of the Przewalski’s horse with its standing mane and large,
donkey-like head. It was probably not coincidental that this equine was
initially described as Asinusprzewalskii.

The records
of three particular individuals from these free-roaming steppe horses are problematic
too. One of them, the “Krim Tarpan”, was suspected to be a feral horse already
back in the 19th century. The purportedly last individual of these
populations, the “Dubrowka Tarpan”, fits the conception of a wild horse except
for its comparably large size (see above), at least according to Heptner 1989.
It is possible that it either a) was indeed a wild horse (wild horses are
usually thought to be smaller, but as I wrote above there is no comprehensive
subfossil record of articulated skeletons ferus-type
wild horses from which we could get an idea of their size, especially not from
the steppe, so we cannot rule out that there were 145cm tall wild horses) b) a
hybrid between a ferus-type wild horse and a feral horse, c) a hybrid between a
Przewalski’s horse and a feral horse, d) a feral horse with some primitive
traits. The most famous of those “tarpan” individuals is the “Cherson tarpan”,
which was caught as a foal in the Ukraine and exhibited in the Moscow Zoo. It
is famous as it is the only “tarpan” that was photographed. It displayed
aggressive behaviour and was castrated, but otherwise showed none of the
suspected wildtype traits clearly. The mane was opulent and long, the legs were
long too, and the colour could have been either bay, seal brown or a very dark
shade of black dun to my eyes. With a size of 133cm at the withers, it fitted
the expected height for wild horses, but so do many rural horses. It could simply
be a feral horse, based on its looks I see nothing compelling that would
qualify it as a genuine, un-hybridized wild horse.

As you see,
there are a lot of open questions, room for interpretation and subjectivity on
this subject. Some of these can only be solved by conducting research (such as
identifying complete osteologic material of genetically proven predomestic
horses, to get an idea of their actual morphology), others probably have to
remain unanswered (such as the status of the historic free-roaming horse
populations, as no specimen are preserved).

The true
nature of Holocene ferus-type wild horses
is of course relevant for ecologic restoration in order to chose horse breeds
that serve as the most authentic proxy. For a number of breeds there are
background stories purported by their advocates as the most authentic and most
“wild” European horses today, which are mostly based on Chinese whispers,
arbitrary interpretations and fabrications. The ferus-type wild horse is as extinct as the aurochs. I already wrote
several posts on this subject. When I can find the time, I am going to do a
similar summary on this issue.

For the
posts that I wrote in the past and used as a basis for this summary, go here:

About this blog

This blog is on everything related to the so-called “breeding-back” of extinct animals: From the extinct animals themselves, over their often domestic descendants and dedomestication to news and facts about various breeding-back projects, reports and photos from my own breeding-back related trips. I try to have a balanced and fact-based approach to this subject and to dismantle many of the popular myths. Enjoy!

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About me

My major interest always have been extinct animals, from dinosaurs to Pleistocene megafauna and more recent extinctions. Besides that I am interested in evolution, genetics and ecology.
I am also an amateur animal artist, making drawings and models mostly of extinct animals.